Battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery pack which comprises a box body, a battery pack, a control valve, a liquid inlet joint and a liquid outlet joint, the box body is provided with a containing cavity, the bottom of the containing cavity is provided with a bottom plate, the battery pack is arranged in the containing cavity, and the bottom plate is provided with a fire-fighting runner and a cooling runner. The fire-fighting flow channel comprises a liquid injection flow channel, liquid injection holes and a first liquid inlet hole, the liquid injection holes communicating with the liquid injection flow channel and the containing cavity are formed in the side, facing the containing cavity, of the bottom plate, and the multiple liquid injection holes are formed in the extending direction of the liquid injection flow channel at intervals. The liquid injection runners are arranged in the bottom plate and extend in the first direction, the liquid injection runners are arranged on the two sides of the battery pack in the first direction, and the cooling runner is arranged between the liquid injection runners on the two sides of the battery pack. The control valve, the liquid inlet connector and the liquid outlet connector are all arranged at the end, in the first direction, of the bottom plate, the liquid inlet connector and the liquid outlet connector communicate with the cooling flow channel, and the control valve communicates with the liquid injection flow channel.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery pack. Background Technology

[0002] In energy storage systems using battery packs as energy storage devices, thermal runaway of the battery packs is a major factor affecting the operational safety of the system. When a battery pack experiences thermal runaway, it releases a large amount of heat and smoke, causing the runaway to spread throughout the system. To improve the safety of the energy storage system, a fire suppression system needs to be installed on the battery packs to control the spread of thermal runaway. However, current fire suppression systems for battery packs are not very effective at controlling thermal runaway, and their presence reduces the efficiency of battery pack installation and removal, thus decreasing the efficiency of energy storage system maintenance.

[0003] Therefore, there is an urgent need for a battery pack to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a battery pack that can effectively control thermal runaway without affecting the cooling effect of the cooling channel on the battery pack, thereby improving the maintenance efficiency of the energy storage system.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A battery pack, having a first orientation, includes: a housing, a battery pack, a control valve, an inlet connector, and an outlet connector;

[0007] The housing has a receiving cavity, the bottom of which is set as a bottom plate. The battery pack is placed inside the receiving cavity, and the bottom plate is provided with fire-fighting flow channels and cooling flow channels.

[0008] The fire-fighting flow channel includes an injection channel, an injection hole, and a first inlet hole. The bottom plate is provided with an injection hole on the side facing the receiving cavity, which connects the injection channel and the receiving cavity. A plurality of injection holes are spaced apart along the extension direction of the injection channel.

[0009] The liquid injection channel is disposed within the base plate and extends along the first direction. The liquid injection channel is disposed on both sides of the battery pack along the first direction. The cooling channel is disposed between the liquid injection channels on both sides of the battery pack.

[0010] The control valve, the liquid inlet connector, and the liquid outlet connector are all located at one end of the base plate along the first direction. The liquid inlet connector and the liquid outlet connector are both connected to the cooling channel. The control valve is connected to the liquid injection channel. The control valve is used to open when the battery pack experiences thermal runaway, so as to inject fire-fighting fluid into the receiving cavity through the liquid injection channel and the liquid injection hole.

[0011] As an improvement to the above technical solution, the battery pack has a second direction that is perpendicular to and intersects the first direction. The fire-fighting flow channel also includes a first flow channel. The first flow channel is disposed between the control valve and the cooling flow channel. The first flow channel extends along the second direction. The liquid injection channels located on both sides of the battery pack are connected to the first flow channel. The first liquid inlet hole connects the control valve and the first flow channel.

[0012] As an improvement to the above technical solution, the cooling channel includes an inlet channel and a return channel disposed within the base plate;

[0013] The inlet channel has a first end and a second end that are arranged opposite to each other along the first direction, and the return channel has a third end and a fourth end that are arranged opposite to each other along the first direction.

[0014] The first end of the liquid inlet channel is connected to the liquid inlet connector, the second end of the liquid inlet channel is connected to the second end of the liquid return channel, and the first end of the liquid return channel is connected to the liquid outlet connector.

[0015] As an improvement to the above technical solution, the bottom plate is provided with a first transfer channel at one end near the liquid inlet connector and a second transfer channel at the other end away from the liquid inlet connector, and both the first transfer channel and the second transfer channel extend along the second direction.

[0016] The inlet channel is provided with a first transfer channel and a plurality of return channels on both sides. The third end of each return channel is connected to the first transfer channel and the fourth end is connected to the second transfer channel. The second end of the inlet channel is connected to the second transfer channel.

[0017] As an improvement to the above technical solution, the bottom plate is further provided with a second flow channel extending along the second direction at one end near the liquid inlet connector. The second flow channel is located on the side of the first transfer channel away from the battery pack. The first transfer channel is connected to the second flow channel, and the second flow channel is connected to the liquid inlet connector.

[0018] As an improvement to the above technical solution, the cooling channel further includes a second liquid inlet and a liquid outlet disposed on the side of the bottom plate facing the receiving cavity, the second liquid inlet and the liquid outlet being disposed on the side of the first flow channel near the battery pack;

[0019] One end of the liquid inlet connector is exposed outside the housing, and the other end extends into the housing and communicates with the second liquid inlet. One end of the liquid outlet connector is exposed outside the housing, and the other end extends into the housing and communicates with the liquid outlet.

[0020] As an improvement to the above technical solution, a detection device is also provided in the receiving cavity, which is used to detect characterization parameters that can reflect the state of the battery pack.

[0021] As an improvement to the above technical solution, the characterization parameters include several of the following: cavity temperature, cavity carbon monoxide concentration, cavity electrolyte volatile gas concentration, cavity smoke concentration, battery pack temperature, and battery pack voltage.

[0022] As an improvement to the above technical solution, the top of the receiving cavity is configured as a top plate, and the battery pack includes multiple battery cells arranged in an array on the bottom plate. Each battery cell has a first side facing the top plate, and an explosion-proof valve is provided on the first side.

[0023] As an improvement to the above technical solution, a pressure relief valve is also included. The circumferential arrangement of the receiving cavity is configured as a side plate, and the pressure relief valve is disposed on the side plate and located at one end of the side plate near the top plate.

[0024] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0025] In the event of thermal runaway, the control valve of this battery pack opens, allowing fire-fighting fluid to be injected into the containment cavity through injection channels and injection holes, submerging the battery pack and preventing the spread of thermal runaway. Injection channels are located on both sides of the battery pack, with multiple injection holes spaced along the extension direction of these channels. During thermal runaway, the fire-fighting fluid injected into the containment cavity through these injection holes can promptly cool various parts of the battery pack. Furthermore, the injection channels on both sides of the battery pack do not interfere with the arrangement of the cooling channels below, ensuring the cooling effect of the cooling channels on the battery pack. In addition, the control valve, inlet connector, and outlet connector are all located at one end of the base plate along the first direction, allowing for quick disconnection and connection of the cooling and fire-fighting systems during installation and replacement of the battery pack, thus improving the maintenance efficiency of the energy storage system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the battery pack structure provided in this embodiment of the utility model. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the battery pack structure provided in this embodiment of the utility model. Figure 2 ;

[0028] Figure 3 This is a cross-sectional view of the battery pack housing provided in this embodiment of the present invention;

[0029] Figure 4This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 1 ;

[0030] Figure 5 This is a schematic diagram of the structure of a single battery cell in the battery pack provided in this embodiment of the utility model;

[0031] Figure 6 This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 2 ;

[0032] Figure 7 This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 3 ;

[0033] Figure 8 This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 4 ;

[0034] Figure 9 This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 5 ;

[0035] Figure 10 yes Figure 9 Sectional view at point AA;

[0036] Figure 11 yes Figure 9 Sectional view at point BB;

[0037] Figure 12 This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 6 ;

[0038] Figure 13 This is a partial structural diagram of the battery pack provided in this embodiment of the utility model. Figure 7 .

[0039] In the picture:

[0040] X, first direction; Y, second direction; Z, third direction;

[0041] 1. Box body;

[0042] 11. Base plate;

[0043] 111. Firefighting flow channel; 1111. Liquid injection flow channel; 1112. Liquid injection hole; 1113. First liquid inlet hole; 1114. First flow passage;

[0044] 112. Cooling channel; 1121. Liquid inlet channel; 1122. Liquid return channel; 1123. First transition channel; 1124. Second transition channel; 1125. Second flow channel; 1126. Second liquid inlet; 1127. Liquid outlet; 1128. Flow hole;

[0045] 12. Top slab; 13. Side slab;

[0046] 2. Battery pack; 21. Battery cell; 211. First side; 2111. Explosion-proof valve;

[0047] 3. Control valve; 4. Inlet connector; 5. Outlet connector; 6. Detection device; 7. Pressure relief valve; 10. Receiving cavity. Detailed Implementation

[0048] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0049] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0050] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0051] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0052] like Figures 1-13 As shown, this embodiment provides a battery pack with a first direction X. The battery pack includes a housing 1, a control valve 3, a battery pack 2, an inlet connector 4, and an outlet connector 5. The housing 1 has a receiving cavity 10, the bottom of which is configured as a base plate 11. The battery pack 2 is disposed within the receiving cavity 10. The base plate 11 is provided with a fire-fighting flow channel 111 and a cooling flow channel 112. The fire-fighting flow channel 111 includes an injection channel 1111, an injection hole 1112, and a first inlet hole 1113. The side of the base plate 11 facing the receiving cavity 10 is provided with an injection hole 1112 that connects the injection channel 1111 and the receiving cavity 10. Multiple injection holes 1112 are spaced apart along the extension direction of the injection channel 1111. The injection channel 1111 is located within the base plate 11 and extends along the first direction X. The battery pack 2 has injection channels 1111 on both sides along the first direction X. The cooling channel 112 is located between the injection channels 1111 on both sides of the battery pack 2. The control valve 3, the inlet connector 4, and the outlet connector 5 are all located at one end of the base plate 11 along the first direction X. The inlet connector 4 and the outlet connector 5 are connected to the cooling channel 112. The control valve 3 is connected to the injection channel 1111. The control valve 3 is used to open in the event of thermal runaway of the battery pack 2 to inject fire-fighting fluid into the receiving cavity 10 through the injection channel 1111 and the injection hole 1112.

[0053] In the event of thermal runaway of the battery pack 2 provided in this embodiment, the control valve 3 opens, and fire-fighting fluid is injected into the receiving cavity 10 through the injection channels 1111 and injection holes 1112, immersing the battery pack 2 in the fire-fighting fluid and preventing the spread of thermal runaway. Injection channels 1111 are provided on both sides of the battery pack 2, and multiple injection holes 1112 are spaced apart along the extension direction of the injection channels 1111. When the battery pack 2 experiences thermal runaway, the fire-fighting fluid injected into the receiving cavity 10 through each injection hole 1112 can promptly cool various locations within the battery pack 2, preventing the rapid spread of thermal runaway within the battery pack 2. Furthermore, the injection channels 1111 located on both sides of the battery pack 2 do not affect the arrangement of the cooling channels 112 below the battery pack 2, ensuring the cooling effect of the cooling channels 112 on the battery pack 2. In addition, the control valve 3, the liquid inlet connector 4, and the liquid outlet connector 5 are all located at one end of the base plate 11 along the first direction X, which allows the cooling system and the fire protection system to be quickly disconnected and connected when the battery pack is installed or replaced, thus improving the maintenance efficiency of the energy storage system.

[0054] Optionally, such as Figures 6-11As shown, the battery pack provided in this embodiment also has a second direction Y that is perpendicular to and intersects the first direction X, and a third direction Z that is perpendicular to and intersects both the first direction X and the second direction Y. The first direction X is the length direction of the housing 1, the second direction Y is the width direction of the housing 1, and the third direction Z is the height direction of the housing 1. The liquid injection channel 1111 extends along the length direction of the battery pack, and multiple liquid injection holes 1112 are spaced apart along the extension direction of the liquid injection channel 1111, thereby ensuring that in the event of thermal runaway of the battery pack 2, the fire-fighting liquid injected into the receiving cavity 10 through each liquid injection hole 1112 can promptly cool various locations of the battery pack 2.

[0055] Optionally, such as Figures 6-13 As shown, the fire-fighting flow channel 111 also includes a first flow channel 1114. The first flow channel 1114 is disposed between the control valve 3 and the cooling flow channel 112. The first flow channel 1114 extends along the second direction Y. The liquid injection channels 1111 on both sides of the battery pack 2 are connected to the first flow channel 1114, so that the liquid injection channels 1111 on both sides of the battery pack 2 are connected as one. The first flow channel 1114 is disposed between the control valve 3 and the cooling flow channel 112 to avoid the presence of the first flow channel 1114 affecting the setting of the cooling flow channel 112, so that the cooling flow channel 112 can completely cover the area below the battery pack 2, ensuring the cooling effect of the cooling flow channel 112 on the battery pack 2. The first inlet hole 1113 connects the control valve 3 and the first flow channel 1114. When the control valve 3 is open, the fire-fighting fluid enters the first flow channel 1114 through the control valve 3 and the injection hole 1112, and flows through the first flow channel 1114 to the injection channels 1111 located at both ends of the first flow channel 1114.

[0056] Furthermore, such as Figure 10As shown, the cooling channel 112 includes an inlet channel 1121 and a return channel 1122 disposed within the base plate 11. The inlet channel 1121 has a first end and a second end disposed opposite to each other along a first direction X, and the return channel 1122 has a third end and a fourth end disposed opposite to each other along the first direction X. The first end of the inlet channel 1121 is connected to the inlet connector 4, the second end of the inlet channel 1121 is connected to the second end of the return channel 1122, and the first end of the return channel 1122 is connected to the outlet connector 5. The first end of the inlet channel 1121 and the third end of the return channel 1122 are both located at the end of the base plate 11 where the control valve 3, inlet connector 4, and outlet connector 5 are installed. This allows the first end of the inlet channel 1121 to connect with the inlet connector 4 for liquid inlet, and the third end of the return channel 1122 to connect with the outlet connector 5 for liquid outlet. The second end of the inlet channel 1121 and the fourth end of the return channel 1122 are located at the other end of the base plate 11 and are connected to each other. This allows the coolant to enter the inlet channel 1121, flow to the other end of the base plate 11 along its length, return through the return channel 1122, and then flow out through the outlet connector 5. This ensures sufficient heat exchange between the coolant and the battery pack 2, guaranteeing the cooling effect of the coolant on the battery pack 2.

[0057] Furthermore, such as Figure 10 As shown, the bottom plate 11 has a first transition channel 1123 at the end near the inlet connector 4 and a second transition channel 1124 at the end away from the inlet connector 4. Both sides of the inlet channel 1121 have the first transition channel 1123 and multiple return channels 1122. The third end of each return channel 1122 is connected to the first transition channel 1123, and the fourth end is connected to the second transition channel 1124. The second end of the inlet channel 1121 is connected to the second transition channel 1124. The first transition channels 1123 on both sides of the inlet channel 1121 connect the return channels 1122 on both sides of the inlet channel 1121 into a single unit, and the second transition channels 1124 connect the inlet channel 1121 and each return channel 1122 into a single unit.

[0058] Furthermore, such as Figure 10 As shown, the bottom plate 11 near the liquid inlet connector 4 is also provided with a second flow channel 1125 extending in the second direction Y. The second flow channel 1125 is located on the side of the first transition channel 1123 away from the battery pack 2. The first transition channel 1123 communicates with the second flow channel 1125, and the second flow channel 1125 communicates with the liquid inlet connector 4. The second flow channel 1125 connects the two first transition channels 1123 located on both sides of the liquid inlet channel 1121 into one unit. In this embodiment, the cooling channel 112 also includes a flow hole 1128, through which the first transition channel 1123 and the second flow channel 1125 communicate.

[0059] Optionally, such as Figures 8-11 As shown, the cooling channel 112 also includes a second liquid inlet 1126 and a liquid outlet 1127 disposed on the side of the base plate 11 facing the receiving cavity 10. The second liquid inlet 1126 and the liquid outlet 1127 are disposed on the side of the first flow channel 1114 near the battery pack 2. One end of the liquid inlet connector 4 is exposed outside the housing 1, and the other end extends into the housing 1 and communicates with the second liquid inlet 1126. One end of the liquid outlet connector 5 is exposed outside the housing 1, and the other end extends into the housing 1 and communicates with the liquid outlet 1127. In this embodiment, both the liquid inlet connector 4 and the liquid outlet connector 5 pass through the first flow channel 1114. The liquid outlet of the liquid inlet connector 4 is disposed at the bottom of the end of the liquid inlet connector 4 that extends into the housing 1, so that the liquid outlet of the liquid inlet connector 4 can communicate with the second liquid inlet 1126. Similarly, the outlet of the liquid outlet connector 5 is located at the bottom of the end of the liquid outlet connector 5 that extends into the housing 1, so that the outlet of the liquid outlet connector 5 can communicate with the liquid outlet hole 1127.

[0060] Optionally, such as Figure 4 As shown, the battery pack provided in this embodiment also includes a detection device 6 disposed within the housing cavity 10. The detection device 6 is used to detect characterization parameters that can reflect the state of the battery pack 2. The characterization parameters include several of the following: temperature of the housing cavity 10, carbon monoxide concentration of the housing cavity 10, electrolyte volatile gas concentration of the housing cavity 10, smoke concentration of the housing cavity 10, temperature of the battery pack 2, and voltage of the battery pack 2. In this embodiment, the detection device 6 includes a fire detector and a BMU (Battery Management Unit). The fire detector monitors the temperature of the housing cavity 10, the carbon monoxide concentration of the housing cavity 10, the electrolyte volatile gas concentration of the housing cavity 10, and the smoke concentration of the housing cavity 10. The BMU monitors the temperature of the battery pack 2 and the voltage of the battery pack 2.

[0061] Optionally, such as Figures 1-4 As shown, the top of the receiving cavity 10 is configured as a top plate 12, and the top plate 12 and the bottom plate 11 are arranged opposite each other along the third direction Z. The battery pack 2 includes a plurality of battery cells 21 arranged in an array on the bottom plate 11. Each battery cell 21 has a first surface 211 facing the top plate 12, and an explosion-proof valve 2111 is provided on the first surface 211. Since the fire-fighting flow channel 111 in this embodiment is located on the bottom plate 11 of the housing 1, in order to prevent the fire-fighting fluid entering the receiving cavity 10 from affecting the exhaust and pressure relief of the battery cell 21 that has experienced thermal runaway when the fire-fighting fluid injection begins in the fire-fighting flow channel 111, the explosion-proof valve 2111 on the battery cell 21 is located on the first surface 211 of the battery cell 21 facing the top plate 12 of the housing 1.

[0062] Furthermore, such as Figure 2As shown, the battery pack provided in this embodiment also includes a pressure relief valve 7. The receiving cavity 10 is circumferentially configured as a side plate 13, and the pressure relief valve 7 is disposed on the side plate 13, located at one end of the side plate 13 near the top plate 12. In order to prevent the fire-fighting fluid from affecting the venting and pressure relief of the battery pack before the receiving cavity 10 is filled, the pressure relief valve 7 of the battery pack in this embodiment is disposed at one end of the side plate 13 near the top plate 12.

[0063] In this embodiment, the battery pack can be equipped with one controller for each battery pack, or multiple battery packs can share one controller. Taking multiple battery packs sharing one controller as an example, the detection device 6 and control valve 3 of each battery pack are electrically connected to the controller. The controller controls the opening and closing of the control valve 3 according to the characteristic parameters detected by the detection device 6. That is, when the controller determines that the battery pack 2 in a certain battery pack is in thermal runaway according to the characteristic parameters, the controller controls the control valve 3 of that battery pack to open. The external fire-fighting fluid supply system injects fire-fighting fluid into the battery pack through the control valve 3 until the battery pack is full of fire-fighting fluid, thereby controlling the thermal runaway within the battery pack and preventing the thermal runaway from spreading and causing losses to other battery packs in the energy storage system. Furthermore, the fire-fighting fluid is directly injected into the battery pack that has experienced thermal runaway and has no effect on other battery packs, thus minimizing the thermal runaway loss. The specific judgment logic of the controller for the characteristic parameters can be specifically set according to needs.

[0064] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A battery pack having a first direction (X), characterized by, The application relates to a battery pack fire extinguishing device, which comprises a box (1), a battery pack (2), a control valve (3), a liquid inlet joint (4) and a liquid outlet joint (5); the box (1) has a containing cavity (10), the bottom of the containing cavity (10) is provided with a bottom plate (11), the battery pack (2) is arranged in the containing cavity (10), the bottom plate (11) is provided with a fire extinguishing flow channel (111) and a cooling flow channel (112); the fire extinguishing flow channel (111) comprises a liquid injection flow channel (1111), liquid injection holes (1112) and a first liquid inlet hole (1113); one side of the bottom plate (11) facing the containing cavity (10) is provided with the liquid injection holes (1112) communicating the liquid injection flow channel (1111) and the containing cavity (10); a plurality of the liquid injection holes (1112) are arranged at intervals along the extension direction of the liquid injection flow channel (1111); the liquid injection flow channel (1111) is arranged in the bottom plate (11) and extends along the first direction (X); the battery pack (2) is arranged on both sides along the first direction (X) and provided with the liquid injection flow channel (1111); the cooling flow channel (112) is arranged between the liquid injection flow channels (1111) on both sides of the battery pack (2); the control valve (3), the liquid inlet joint (4) and the liquid outlet joint (5) are arranged at one end of the bottom plate (11) along the first direction (X); the liquid inlet joint (4) and the liquid outlet joint (5) are communicated with the cooling flow channel (112); the control valve (3) is communicated with the liquid injection flow channel (1111) and is used for being opened when the battery pack (2) is in thermal runaway to inject fire extinguishing liquid into the containing cavity (10) through the liquid injection flow channel (1111) and the liquid injection holes (1112). The fire extinguishing flow channel (111) further comprises a first overflow flow channel (1114) arranged between the control valve (3) and the cooling flow channel (112); the first overflow flow channel (1114) extends along the second direction (Y) and is communicated with the liquid injection flow channels (1111) on both sides of the battery pack (2); the first liquid inlet hole (1113) is communicated with the control valve (3) and the first overflow flow channel (1114). The cooling flow channel (112) comprises a liquid inlet flow channel (1121) and a liquid return flow channel (1122) arranged in the bottom plate (11); The liquid inlet flow channel (1121) has a first end and a second end arranged oppositely along the first direction (X); the liquid return flow channel (1122) has a third end and a fourth end arranged oppositely along the first direction (X); 2. The battery pack according to claim 1, having a second direction (Y) perpendicular and intersecting the first direction (X), characterized in that, The first end of the liquid inlet flow channel (1121) is communicated with the liquid inlet joint (4); the second end of the liquid inlet flow channel (1121) is communicated with the second end of the liquid return flow channel (1122); the first end of the liquid return flow channel (1122) is communicated with the liquid outlet joint (5).

3. The battery pack of claim 2, wherein, ​ ​ ​ 4. The battery pack of claim 3, wherein, The bottom plate (11) is provided with a first adapter flow channel (1123) near one end of the liquid inlet connector (4) and a second adapter flow channel (1124) away from the liquid inlet connector (4), and the first adapter flow channel (1123) and the second adapter flow channel (1124) both extend along the second direction (Y); The liquid inlet flow channel (1121) is provided with the first adapter flow channel (1123) and a plurality of liquid return flow channels (1122) on both sides, the third end of each liquid return flow channel (1122) communicates with the first adapter flow channel (1123), the fourth end of each liquid return flow channel (1122) communicates with the second adapter flow channel (1124), and the second end of the liquid inlet flow channel (1121) communicates with the second adapter flow channel (1124).

5. The battery pack of claim 4, wherein, The bottom plate (11) is further provided with a second overflow flow channel (1125) extending along the second direction (Y) near one end of the liquid inlet connector (4), the second overflow flow channel (1125) is arranged on the side of the first adapter flow channel (1123) away from the battery pack (2), the first adapter flow channel (1123) communicates with the second overflow flow channel (1125), and the second overflow flow channel (1125) communicates with the liquid inlet connector (4).

6. The battery pack of claim 4, wherein, The cooling flow channel (112) further comprises a second liquid inlet hole (1126) and a liquid outlet hole (1127) arranged on the side of the bottom plate (11) facing the containing cavity (10), and the second liquid inlet hole (1126) and the liquid outlet hole (1127) are arranged on the side of the first overflow flow channel (1114) close to the battery pack (2); One end of the liquid inlet connector (4) is exposed outside the box (1), and the other end extends into the box (1) and communicates with the second liquid inlet hole (1126), and one end of the liquid outlet connector (5) is exposed outside the box (1), and the other end extends into the box (1) and communicates with the liquid outlet hole (1127).

7. The battery pack of claim 1, wherein, Further comprising a detection device (6) arranged in the containing cavity (10), the detection device (6) is used for detecting a characteristic parameter capable of reflecting the state of the battery pack (2).

8. The battery pack of claim 7, wherein, The characteristic parameter includes several of the containing cavity (10) temperature, the containing cavity (10) carbon monoxide concentration, the containing cavity (10) electrolyte volatile gas concentration, the containing cavity (10) smoke concentration, the battery pack (2) temperature and the battery pack (2) voltage.

9. The battery pack of any one of claims 1-8, wherein, The top of the containing cavity (10) is provided as a top plate (12), the battery pack (2) comprises a plurality of battery cells (21) arranged in an array on the bottom plate (11), the battery cell (21) has a first surface (211) facing the top plate (12), and the first surface (211) is provided with an explosion-proof valve (2111).

10. The battery pack of claim 9, wherein, Further comprising a pressure relief valve (7), the containing cavity (10) is circumferentially provided as a side plate (13), and the pressure relief valve (7) is arranged on the side plate (13) and located at one end of the side plate (13) close to the top plate (12).

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